Package org.apache.maven.impl.cache

Class CachingSupplier<REQ,REP>

java.lang.Object

org.apache.maven.impl.cache.CachingSupplier<REQ,REP>

Type Parameters:

REQ - The request type

REP - The response type

All Implemented Interfaces:

Function<REQ,REP>

public class CachingSupplier<REQ,REP>
extends Object
implements Function<REQ,REP>

A caching supplier wrapper that caches results and exceptions from the underlying supplier. Used internally to cache expensive computations in the session.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	CachingSupplier.AltRes	Special holder class for exceptions that occur during supplier execution.

Field Summary

Fields

Modifier and Type	Field	Description
protected final Function<REQ,REP>	supplier
protected Object	value

Constructor Summary

Constructors

Constructor	Description
CachingSupplier(Function<REQ,REP> supplier)

Method Summary

Modifier and Type	Method	Description
REP	apply(REQ req)
void	complete(Object result)	Directly sets the cached value without invoking the supplier, then notifies any threads blocked in apply(Object) waiting for the result.
Object	getValue()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.function.Function

andThen, compose

Field Details

supplier

protected final Function<REQ,REP> supplier

value

protected volatile Object value

Constructor Details

CachingSupplier

public CachingSupplier(Function<REQ,REP> supplier)

Method Details

getValue

public Object getValue()

complete

public void complete(Object result)

Directly sets the cached value without invoking the supplier, then notifies any threads blocked in apply(Object) waiting for the result.

This is used by AbstractRequestCache.requests(java.util.List<REQ>, java.util.function.Function<java.util.List<REQ>, java.util.List<REP>>) to set batch-resolved results on CachingSupplier instances. Concurrent callers blocked in apply() will be woken up and see this value instead of invoking the supplier redundantly.

Parameters:

result - the result to cache (may be a normal result or an CachingSupplier.AltRes for errors)

apply

public REP apply(REQ req)

Specified by:

apply in interface Function<REQ,REP>